Inductance



Jan. 12 3926. 1,569,604

E. F. ANDREWS INDUGTANCE Filed Dec. 51, 1924 WM WM, ,m d F/m g Patented Jan. 12,

PATENT OFFICE.

EDWARD IE. ANDREWS, OF CHICAGO, ILLINOIS.

IN DUCTAN'GE.

Application filed December 31 1924. Serial No. 758,986.

To all whom it may concern:

Be it known that I, EDWARD F. ANDREWS, a citizen of the United States, and resident of Chicago, in the county of Cook and State of Illinois, have invented a-certain new and useful Improvement in .Inductances, of which. the following is afull, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification. My invent-ion relates to an inductance device for use as. an element a radio receiving set. It is desirable that inductances for use in radio frequency circuits have low distributed capacity and low resistance, but that they shall have a large inductance relative to the distributed capacity confined within a smallspace. My structure possesses advantages-as to all of the foregoing features, and in addition thereto is simple and inexpensive to manufacture, sturdy in structure, and convenient in form.

In general, my invention comprises a plurality of slotted plates of insulating material supported radially about one or more central insulating discs, the wires forming the inductance being wound in the slots in said plates and forming a plurality of spaced pancakes, each one wire in thickness, the outer layer of wire on each pancake being connected to the inner layer of wire on the adjacent pancake where several pancakes are comprised within the same winding on the inductance. Each inductance device may include several windings, which windings may, if desired, comprise one or more pancackes.

My invention is illustrated in the accompanying drawing, in which- Figure 1 is a side elevation of a two coil inductance Figure 2 is an end elevation of the same inductance; 4

Figure 3 is a section taken on the line 3-3 of Figure 2; j Figure 4 is one of the discs for supporting the plates; and i I F1gure 5 is one of the slotted plates. In the particular embodiment here shown, a pair of circular discs 6 and '2 are slotted at 8 to receive plates 9 in radial position, making a paddle wheel structure. Each of the plates 9 is provided with a plurality of slots 11" each of the width of the insulated wire 12 which is wound in the slots in pancake form.

The particular inductance here illustrated s provided with a primary winding 14: and asecondary winding 15. The I primary winding is confined to the left-hand slot (Fig. l) and has its terminals connected with the posts 16 and 17 conveniently mounted upon the disc 6 by means of hollow rivets 18. The secondary winding occupies seven slots and comprises a continuous winding starting at the bottom of the right-hand slot (Fig. 1) and continuing from the-top or outer part of this slot to the bottom of the next slot, and in like manner through all of the slots. The end of the secondary winding leading from the outer part of the slot adjacent the primary winding is attached to the supporting post 20, the other end of the secondary winding bein connected to the terminal 21 mounted on t edisc 7 The coil is conveniently supported by a pair of angles 22 and 23, these bein preferably s aced from the ends of the coil by insulating ushings 24. 1

Some of the advantages which are realized from the foregoing invention are:

First: The construction facilities winding the adjacent pancakes of the same coil all from the inside of the -slots to the outside thereof, so that the conductors of adjacent pancakes which have the greatest difference of potential will lie the greatest distance apart; that is, at the bottom of one slot and the top of the adjacent slot.

Second: A very small amount of dielectric material lies in contact with the COD:

doctors, and that which is spaced away from the conductors is located ina low electrostatic field.

Third: The terminal ofthe secondary coil,

comparatively the potential of which is high with res act to the terminals of the primary coi is mounted upon a separate piece of insulating dielectric, wherebythe capacitative coupling between the secondary and primary coils is less than it would be if these terminals were adjacent one another on the same piece of dielectric material.

Fourth: By winding these inductances on a winding machine, the pressure between adjacent conductors may be maintained con Fifth: The inductance may be connected into the circuit such that the grounded end of the secondary coil forms a shield to minimize capacitative coupling between the secondary and the primary windings. This same feature tends to diminish the distributed capacity of the secondary coil, since each pancake of the coil forms a shield against the capacitative coupling between the pancakes on its alternate sides.

Sixth: An inductance wound in this manner has an advantageous space insulation resulting from the fact that the various pancakes of turns are spaced from one another with air separation, except at a few intervals where the windings contact with the thin edges of the dielectric.-

Seventh: The arrangement facilitates the construction of a given inductance having very low distributed capacity and resistance confined within a small space and one which needs no lacquer or other binding dielectric coating for providing the necessary strength tohold the inductance in shape. I

Having thus described my invention and the advantages thereof, I desire it to be understood that the same advantages may be gained through slight modifications in the construction lying within the purview of my invention.

What I claim is:

1. A supporting device for an electrical inductance comprising a disc, the periphery f which is provided with a pluralitv f substantially radial slots, a plurality of dielectric plates adapted to fit snugly in the said radialslots of said disc, each plate being also slotted so as to morticeover the said disc, and wires of an electrical inductance supported by the external edges of said plates. i

2. A supporting device for an electrical inductance comprising a pair of parallel discs, each having a plurality of radial slots extending inwardly from the peripheries of said discs to substantially equal distances from the centers of said discs, anda plurality of dielectric plates each provided with a pair of slots for morticing with the slots in the peripheries of said discs, the exterior edges of said plates being adapted to support the conductors of an electrical inductance.

In witness whereof, I hereunto subscribe my name this 24th day of December, 1924.

EDWARD F. I ANDREWS. 

